Infant HBV Vaccination May Not Save Teens from Hepatitis

You make sure your kids get all sorts of jabs when they’re young, to protect their future wellbeing. However, a new study has shown that family wellness may not be safe from hepatitis B virus infection, even with a complete vaccination series.

According to the study from Taiwan, teens with high-risk mothers (those positive for HBeAg) and teens whose immune system fails to remember a previous viral exposure (immunological memory) are behind HBV re-infection. This is a major global health concern, with two billion individuals worldwide having HBV infection and 360 million chronic carriers of the hepatitis B surface antigen (HBsAg), say the World Health Organization.

Taiwan has been an endemic area of HBV infection for a long time, with a rate of 95% and 20% of the general population carrying HBsAg. The researchers say this is largely caused by vertical or mother-to-child transmission, which is what caused Taiwan in launch the world’s first universal vaccination program in 1984, vaccinating newborns of infectious mothers then expanding to all newborns in 1986.

According to lead author, Dr. Li-Yu Wang from Mackay Medical College in New Taipei City, Taiwan, ‘Chronic HBV is a major health burden that leads to cirrhosis, liver cancer (hepatocellular carcinoma) and liver failure, shortening lives and placing a huge economic drain on society’.

Wang said ‘While infantile HBV vaccination is highly effective, it is not 100% and our study examines the long-term success of the HBV vaccine in a high-risk population.’ The team assessed 8733 high school students born between July 1987 and July 1991 and their vaccination records for the presence of HBsAg and antibodies to HBsAg (anti-HBs). They found that 15% of the students who received the HBV immune globulin (HBIG) and vaccine as were positive for HBsAg.

The team noted that previous research has proven that the vaccine programme did reduce HBV infection and carrier rates of children in Taiwan, as well as a decline in severe hepatitis in infants and liver cancer in children. The team suggested that further, large-scale studies could help to determine the safety and efficacy of giving routine anti-HBV treatment during pregnancy to further reduce infant exposure to the virus.

Wang concluded ‘Certainly the HBV vaccine program was a great success in Taiwan. For adolescents who lose protection, a HBV vaccination booster at age 15 or older should be considered, particularly in those born to HBsAg positive mothers or who had a high-risk of HBV exposure. Those born to high-risk mothers should first be screened for HBsAg.’